• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.369-376
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• 2021

The International Maritime Organization has developed the Energy Efficiency Design Index, an index related to carbon dioxide emissions, to enforce regulations on newly built ships. In this study, a new type of energy-saving device called the ring stator was used for 158k crude oil carriers, whose hull form was developed as a very thin after-body hull to reduce the resistance by delaying separation. The Energy-Saving Device (ESD) particularly involving the duct, is not adapted to the thin-after body hull form-like container ship. This new ring stator was developed considering these characteristics. A parametric study was conducted through Computational Fluid Dynamics (CFD) analysis using the Star-CCM+ program, and approximately 3.4 % improvement in propulsion efficiency was achieved. Further optimization investigations and experimental studies should be conducted in the future.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.338-341
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• 2011

Water usage for cleaning the toilet bowl accounts for 27% of the total water usage. Water-saving valve that can select the amount of water for cleaning toilet bowl can be reduced expenditure. After installing water-saving valve, analysed the economic effects. Water-saving valves compared with flush valves, and researched the amount of water usage. Then analyzed fort he economic effects. Water-saving valve was used 5.6 ${\ell}/time$ for cleaning toilet bowl. In contrast, flush valve was consumed 8.4 ${\ell}/time$. Water-saving valve's water-saving rate was 33.3%. The initial payback period for Water-saving valve was 459.5 days. By a small investment in water saving valve, the economic benefits can be obtained.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.2
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• pp.390-398
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• 2015

Energy-saving devices for 317K VLCC have been developed from a propulsion standpoint. Two ESD candidates were designed via computational tools. The first device WAFon composes of flow-control fins adapted for the ship wake to reduce the loss of rotational energy. The other is WAFon-D, which is a WAFon with a duct to obtain additional thrust and to distribute the inflow velocity on the propeller plane uniform. After selecting the candidates from the computed results, the speed performances were validated with model-tests. The hydrodynamic characteristics of the ESDs may be found in improved hull and propulsive efficiencies through increased wake fraction.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.6
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• pp.880-886
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• 2010

In this paper, we studied the application of low pressure ultra-violet (UV) lamps for the development of an energy saving ship's ballast water treat (BWT) device. We proposed the optimal arrangement of UV lamps by analyzing the energy radiated from medium- and low-pressure UV lamps. Based on the experimental results, we manufactured a disinfection chamber which is composed of low-pressure UV lamps. The rated power and the treatment capacity of the chamber are 216 [W] and 10 [$m^3$/h], respectively. This can replace a disinfection chamber treated by two 2 [kW] medium pressure lamps. The disinfection performance, however the power consumption is about one-eighteen compare to the medium pressure UV lamp, is over 94 [%] for bacteria, 93 [%] for zooplankton, and 94 [%] for phytoplankton. Therefore, it would be possible to develop an energy saving BWT device in a low capacity below 100 [$m^3$/h].

• Journal of Navigation and Port Research
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• v.40 no.4
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• pp.165-171
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• 2016

SEEMP (Ship Energy Efficiency Management Plan) has entered into force since 2013 for the reduction of GHG emission of operating ships. SEEMP guidelines include the hardware modification or installation of energy-saving device on ship. It also includes software based energy-saving technology such as optimum routing, speed optimization, etc. Hardware based technologies are not easy to apply to ongoing vessel due to the operational restriction. Therefore, IT based energy-saving technology was applied and its energy efficiency was evaluated using before and after energy-saving system applied voyage data. SEEMP advises a voluntary participation of EEOI (Ship Energy Efficiency Operation Indicator) use as an indicator of ship energy efficiency operation, and those results were also shown to evaluate the improvement efficiency of energy-saving system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.576-582
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• 2016

To cope with international regulations, such as Energy Efficiency Design Index (EEDI), Ship Energy Efficiency Management Plan (SEEMP) and so forth, and to enforce limitations on $CO_2$ emissions, green-ship technology to lower fuel consumption has been actively researched, and the development of an energy-saving device (ESD) is being pursued. In order to design an ESD for small and medium-sized domestic vessels, an analysis on flow characteristics has been performed in the present study. Through a model test and numerical analyses, the characteristics of flow around the stern bilge and bulb have been compared to improve wake quality and resistance performance. As a result of these comparisons and analyses, a vertical plate has been adopted,, as a new ESD. Design criteria for the proposed ESD are also suggested. By applying this new ESD, it is expected that the total resistance and average nominal wake can be reduced by 3.04 % and 18.8 %, respectively.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.9
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• pp.27-34
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• 2018

The purpose of this study is to demonstrate and analyze the function of a Smart Plug before and after it is applied on the electrical appliances by controlling standby power usage. The research measures and analyzes the amount of electrical energy used while activating the Smart Plug with two types of appliances in a university facilities. The smart plugs were applied into a Group 1 appliances (Multi-function device, computer, laptop, Air con) which completely hinder the standby power, and a Group 2 appliances (Refrigerator, cold and hot water dispenser) which does not completely hinder the standby powers due to the characteristics of the function. First, the total standby power saving of all electrical appliances (Group 1 and Group 2) using the Smart plug was measured as 4.59%. Second, the energy saving of the Group 1 products was analyzed as 26.43%. Third, the standby power saving of the air conditioners from mid October to early December was measured as 31.06%, during the seasons when air conditioning was not actively in use. The research indicates that all specified appliances did have better energy efficiency with the Smart plug regardless of the amount of energy usage.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.10
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• pp.656-661
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• 2011

The amount of water resources that can be used tend to be decreased gradually. In contrast, the rapidly increasing water consumption is a problem that need to be addressed. Renovation and equipment replacement to improve energy efficiency and to reduce expenditure for building usage is required. But the excessive initial investment cost and the prolonged of pay back period may be uneconomical choice. Water usage for cleaning the toilet bowl accounts for 27%of the total water usage. Water-saving valve that can select the amount of water for cleaning toilet bowl can be reduced expenditure. After installing water-saving valve, analysed the economic effects. Water-saving valves compared with flush valves, and researched the amount of water usage. Then analyzed for the economic effects. Water-saving valve was used 5.6 ${\ell}$/time for cleaning toilet bowl. In contrast, flush valve was consumed 8.4 ${\ell}$/time. Water-saving valve's water-saving rate was 33.3%. The initial payback period for Water-saving valve was 459.5 days. By a small investment in water saving valve, the economic benefits can be obtained.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.17-23
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• 2012

In this paper, we were proposed a new LED light device lighting control algorithm for optimal energy saving. The propose lighting control algorithm be to the LED lights devices lighting control by measuring illuminance into multi sensors. And it be to lighting control by inverting of octagon pattern during set-up time. All the LED is lighting when detecting motion by the motion sensor. And, it was designed enable remote management control by communicate with central monitoring center using Zigbee wireless network to measured data from sensors at real time. In this paper, a proposed lighting control algorithm was measured power consumption about the lighting status of LED lighting device using the lighting control program for demonstrate of energy savings effect. The measured result, the lighting method applying proposed algorithm were proved energy savings effect of more 40% more compared to the existing lighting method.

• 한국기계연구소 소보
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• s.17
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• pp.177-187
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• 1987

This report describes the study result of the hydrodynamics characteristics for the wake duct. Two wake ducts for the DWT 25,000 Product Carrier were designed and manufactured. The resistance and propulsion performance of the model with them was evaluated by model tests. The object of the present research for the wake duct is to establish the foundation of the design technique and the performance prediction ability of the one, and furthermore, to prepare the base of the development of new type energy saving device